1. Field of the Invention
The invention relates to a vehicle including a control device that executes rectangular-wave control (rectangular-wave voltage control) over a motor using an output of a resolver, and a control method for the vehicle.
2. Description of Related Art
Japanese Patent Application Publication No. 2008-283751 (JP 2008-283751 A) describes a technique for, in a system that drives a motor in a rectangular-wave control mode, preventing disturbing torque fluctuations by computing a motor command current vector and a motor detected current vector for torque control on the basis of a rotor rotation position detected by a rotor rotation position sensor and then correcting the phase of a rectangular-wave voltage such that a deviation between an estimated torque obtained from the motor command current vector and an estimated torque obtained from the motor detected current vector becomes zero.
Incidentally, a sensor called resolver is generally used for the sensor that detects a rotor rotation position, and a detected value of the resolver may include a so-called zero offset error. Therefore, it is desirable that control for calculating the zero offset error (hereinafter, also referred to as “zero learning”) be executed and then the detected value of the resolver be corrected on the basis of the result. However, if zero learning has not been completed, there is a concern that an error arises in estimated torque due to the influence of the zero offset error and, as a result, the output torque of the motor rapidly varies.